DNA IMAGE CYTOMETRY OF PROSTATIC-CARCINOMA - A COMPARISON OF NEEDLE CORE BIOPSY AND SUBSEQUENT PROSTATECTOMY SPECIMENS

DNA ploidy has recently been identified as an objective prognostic fac tor in prostatic carcinoma. Although the diagnosis of prostatic carcin oma is increasingly being made with the use of needle core biopsies, t he optimal method for the cytometric analysis of these specimens has y et to be determined. In addition, the degree to which the biopsy is re presentative of the subsequent prostatectomy specimen with respect to DNA heterogeneity has not been adequately addressed. In this study, im age cytometric (ICM) DNA analysis was performed on tissue sections fro m 12 prostatic needle core biopsies and the results were compared with similar ICM analysis of the subsequent prostatectomy specimens. Multi ple blocks (n = 48) of the prostatectomy specimens were utilized to pr epare tissue sections and nuclear suspensions and each set of preparat ions were analyzed by ICM in a parallel comparison study. There was co ncordance of 0.80 in the classification of DNA diploid and aneuploid t umors by ICM analysis of tissue sections and nuclear suspensions from paraffin blocks. In all of the discordant cases, DNA aneuploid populat ions were identified by ICM analysis of tissue sections only. This is attributed to difficulties in obtaining a representative nuclear suspe nsion from disaggregated paraffin-embedded prostatic tissue which ofte n has a very desmoplastic stroma. ICM analysis of tissue sections seem s to be an optimal method for DNA ploidy analysis of prostatic carcino ma and is well suited to small volume biopsy material. Determination o f DNA ploidy status in prostatic biopsies was predictive of the subseq uent prostatectomy specimens with a concordance of 0.92.